Not building heat

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gliderider06

gliderider06

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Hi gang, got a heating issue with my Ramcharger. It barely comes up to the first mark on the gauge. I recently replaced the radiator with an aluminum 4 core unit. With the factory one, the gauge was in the center after the same half hour trip to work. I thought I had a 160* stat in it, but I replaced a 195* with a 195* so that wasn't it. I have a thermal fan clutch on it and I wonder if that is the culprit. It has very little free spin on it cold or hot.
I'm thinking about replacing it but would it be better to get a non thermal or thermal clutch for the winter?
Any other suggestions?
Thanks!
 
Have you checked it with a back up tester like a water thermometer or an IR gun?
Have you tested the rad temperature?
The stat sets the minimum water temperature, so it's job is to stay CLOSED until it's calibration point. It doesn't care about the rad or the clutch. But it does care about the heater core.
If your heater is blowing hot, and set on full-bore, it is extracting a lotta heat.
With the stat closed, the hot water from the intake manifold is sent thru the bypass hose and back into the pump. So the heated water is going round for another trip. Eventually the water gets hot enough to open the stat, and most of the hot water goes to the rad, then the pump starts pulling in the cold water. If the water temp falls below the stat's set point, it begins to close again. And so it continues.

The only ways to make the engine run hotter, than the set point are:
1) make it work harder
2) retard the ignition timing
3) lean it out (make sure the choke is coming off)
4) Change the coolant medium
5) slow the pump down
6) put a parka on it
 
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After getting home today I let it idle In the garage and it came up some in temp. I have it at 12* initial and 34* total before vacuum advance, whatever that is with the MSD distributor. On really cold days I think the choke is staying closed some.(I disconnected the cold air tube to the aircleaner as well) Edelbrock 1406 carb. Its getting worse than normal fuel mileage also. It gets warm in the truck but it takes a little bit and not hot like it has in the past.
I'll look at changing the metering rod springs to lighter ones and see if that helps any.
Thanks!
 
  1. Did the heater work properly before that change?
  2. Does the heater work properly after the change?
  3. Did you get all the air out of the system?
  4. When the engine is cold and running, if you take off the rad cap is water circulating in the rad?
 
BTW
if the temp sensor is NOT in the water, it will NOT measure the temp of the water. It will give try to give you the temp of the air above the water, but it's really lousy at doing that.
So if you have used a stack of adapters to make your sensor "fit" well there yago. fix it.
If you wait long enough, the airwill eventually work it's way out of the standpipe, but that water will be stagnant in there, and the adapters will radiate the heat away faster than had it been inside the intake properly, and no matter what you do, it will always read low..
 
Dana67Dart said:
  1. Did the heater work properly before that change?
  2. Does the heater work properly after the change?
  3. Did you get all the air out of the system?
  4. When the engine is cold and running, if you take off the rad cap is water circulating in the rad?
Click to expand...
Heat worked great before new radiator.
Gets warm, not as warm as before.
No air in system and I can see coolant flowing through the radiator.
I had to change it since the original had sprung more leaks than the Titanic.
This is why I think the fan clutch is hanging up and not spinning freely at 55mph.
 
AJ/FormS said:
BTW
if the temp sensor is NOT in the water, it will NOT measure the temp of the water. It will give try to give you the temp of the air above the water, but it's really lousy at doing that.
So if you have used a stack of adapters to make your sensor "fit" well there yago. fix it.
Click to expand...
Good point. I'm using a factory cast iron intake and sending unit. I will use my IR thermometer when I get it to work tomorrow and see what It reads.
Thank you!
 
gliderider06 said:
No air in system and I can see coolant flowing through the radiator
Click to expand...
If the radiator is flowing water when the engine is cold the thermostat is likely stuck open, blocked open, not seating propperly allowing coant to flow through the radiator.

As AJ/Formulas mentioned the thermostat sets the low temp.

If it is open the coolant will circulate in the radiator and cool the engine excessive.

Had that happen once here in Colorado in winter, drove 40 miles on the interstate, pulled into a gas station and the radiator hoses were barely warm, hence no heat or defrosters. I had a 10 inch opening on the fogged up window to see where I was going.


IMHO

Before you spend any time "fixing" the things you did not touch diagnose the problem to the likly things that you did touch.

  1. The fan will not be the problem at any speed over 25 to 30 mph.
  2. Water flowing in the radiator when the engine is cold suggests the thermostat is allowing coolant to flow cooling the engine too much
  3. Unless you changed other things when you changed the rad, the carb, tune, timing, choke etc are not the problem
 
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^ This. Aluminum does shed heat faster than copper/brass, but I'm betting on a bad new thermostat.
 
My first check would be the thermostat. If you pull the thermostat and it is closed, you can check its operation in a pot of water on the stove and a meat thermometer and watch to see when it opens. As temp rises the tstat will begin to open up slowly until it hits the set 195 degrees give or take a few, at which time it should be fully open.
 
Kendog 170 said:
Brand new t-stats can be faulty. Ask me how I know.
Click to expand...
yup i agree, they can be bad out the box. Here in canada, we can get 205 thermostats, really makes a difference on the cold days. We also use winter fronts or cardboard partially covering the rad.
Click to expand...
 
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theyre-right-you-know.jpg
 
Had this happen with a Ford, there was just enough of a gap in the rad hose to pull air into the cooling system.
 
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